90toy4x4

1990 22re auto 4x4
I have replaced the thermostat and radiator cap with new.
The overflow tank is constantly over the full mark, to the point that it overflows. I have not seen it overflow but there is coolant covering everything near the tank. It will not suck any coolant back into the radiator.
The temp gauge typically never gets to the actual temp symbol, never really fluctuates.... unless it is low on coolant, then it will overheat.
I have also tried draining the system, refilling, and burping. I did notice when checking to make sure that the thermostat was in correctly, that the coolant seemed pressurized under the thermostat. It was gushing up out of the tiny hole in the housing of the stat.
When the engine is warm, all the hoses are hot and pressurized, no hose is hotter/more pressurized than the other.
I am at my witts end with this. Can someone give me any pointers/tips on what i am overlooking?!

rworegon

Start checking for a failed HG.....a failed HG will over pressurize the cooling system as you describe.

hambob

I had a 95 3vze and it would constantly bubble in the overflow reservoir. I had a blown HG. Check under the oil fill cap and see if there is any creamy stuff. That will mean coolant and oil are mixing somewhere(blown HG).

Good luck!!

gennro

Yop, I agree a blown headgasket will cause this.

90toy4x4

It doesn't bubble in the tank, only when I pull the radiator cap. I checked the oil and it looks like oil should, same with coolant, same with exhaust. From what I've researched, a HG leak can still leak without the coolant and oil mixing, is this true?

gennro

Yes, I have blown headgaskets like this before. You are more likely to blow a headgasket where it goes into a coolent passage then into an oil passage on a 22r. Easiest way to figure out which one is after the engine is nice and hot shut off the engine and pull each plug till you find one soaked with coolent or coolent in the cylinder. Reason why this happens is the coolent system is pressurized and will push the coolent back into the cylinder after the engine is shutdown.

rworegon

Time for a leak down test. Pull the plugs and take a look into the cylinders.

90toy4x4

Oh man. Haven't done a leak down test in quite some time. I will have to get on that this weekend.
Why would it not suck the coolant back into the radiator when it cools down

toyota4x4907

The lower radiator hose should be cooler than the upper...

But it still sounds exactly like when the HG in my 22re went out.

90toy4x4

It is slightly cooler. Just not that noticeable, nothing like half the temp of the upper hose. I'm assuming the upper is the return line?

malteserunner

iTrader: (1)

You can also get a cooling system pressure tester, to pressurize the system with the engine cold. Then you can pull the plugs, and check for coolant in the cylinders. It sounds like a blown HG or cracked head. O'Reilly will loan you the pressure tester. Other parts stores will probably have them too. Good luck.

RAD4Runner

Agree with bad head gasket as suspect. Actually blew the radiator cap on my Civic.

Let engine cool down, take radiator cap off. Start engine. Bad head gasket would cause coolant to splash out of radiator. Need to distinguish from splashing due to engine vibration.

TNRabbit

A coolant pressure tester is much more reliable method than a leakdown test. Remove the plugs FIRST~